via Wikipedia: The duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of th

via Wikipedia: The duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. So I guess that means a meter is 30.66331898849836976219 cesium-133 transition periods.